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Global Accelerator

Links: 101 AWS SAA Index

  • When you go to Global Accelerator it goes to us-west-2
  • Global accelerator uses the concept of Anycast IP.
  • Unicast IP: one server holds one IP address
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  • Anycast IP: all servers hold the same IP address and the client is routed to the nearest one

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  • Global accelerator uses the AWS Global network. This minimises latency since over public internet the connection has to go over a lot of hops which can add latency.

How does Global Accelerator work?
  • In global accelerator 2 anycast IPs are created.
  • Traffic is directly sent to the edge location.
  • The edge locations send traffic to our application over the private global AWS network.

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  • It has DDoS protection with the help of AWS Shield.
  • Global health checks for automatic failover.

  • Intelligent routing to lowest latency.

  • It provides static IP addresses that provide a fixed entry point to your applications and eliminate the complexity of managing specific IP addresses for different AWS Regions and Availability Zones.

  • Global Accelerator is a good fit for non-HTTP use cases, such as gaming (UDP), IoT (MQTT), or Voice over IP.

  • It works with:

    • Elastic IP
    • EC2 instances
    • ALB and NLB either private or public.
Whenever you see these keywords like these then go for AWS Global Accelerator.
  • 2 static IP addresses
  • AWS Global network
  • Automatic failover
  • routing to the closest region
  • TCP/UDP
  • latency
  • doesn't want to change their DNS service
You want to do blue green deployment and most of the customers use mobile phones which are prone to DNS caching.

AWS Global Accelerator uses endpoint weights to determine the proportion of traffic that is directed to endpoints in an endpoint group, and traffic dials to control the percentage of traffic that is directed to an endpoint group.

While relying on the DNS service (Route53) is a great option for blue/green deployments, it may not fit use-cases that require a fast and controlled transition of the traffic. Some client devices and internet resolvers cache DNS answers for long periods. The downside of this in blue/green deployments is that you don't know how long it will take before all of your users receive updated IP addresses when you update a record, change your routing preference or when there is an application failure. With AWS Global Accelerator, you can shift traffic gradually or all at once between the blue and the green environment and vice-versa without being subject to DNS caching on client devices and internet resolvers, traffic dials and endpoint weights changes are effective within seconds.

Difference between CloudFront and Global Accelerator

  • Both of them make use of the edge locations
  • Both services integrate with AWS Shield for DDoS protection.
  • CloudFront caches the content and then delivers it whereas Global Accelerator is like a proxy to the region your application is in.
  • In case of CloudFront content is served from Edge (in case of cache hit) whereas in Global Accelerator it is served from the region your application is hosted.
  • Global Accelerator is good for HTTP use cases that require static IP addresses.

Last updated: 2022-05-01